sprang, which, according to tradition, prevailed with some, that the object of the institution was to favor religious infidelity." The constitution of the society was agreed upon on the 17th of March, and the name Academy of Natural Sciences was adopted on the 21st of that month, which date was established as that of the beginning of the institution. On that day, too, the members agreed "to contribute to the formation of a museum of natural history, a library of works of science, a chemical experimental laboratory, an experimental philosophical apparatus, and every other desirable appendage or convenience for the illustration and advancement of natural knowledge, and for the common benefit of all the individuals who may be admitted members of our institution." Among the first donors of minerals were Dr. Troost, Mr. Isaac Lea, Dr. Hays, and Mr. S. Hazard. When the small room, 121 North Second Street, hired about the 1st of April, was occupied, the members came forward with their gifts to serve as the nucleus of the museum and library. Among them was Dr. Troost, with some artificial crystals, prepared by himself. On the occasion of the election of officers, May 7, 1812, Dr. Troost was chosen president. He held this office five years, or till 1817, when he resigned and was succeeded by William Maclure. On the 15th of August, 1812, the collection of minerals previously purchased from Dr. Seybert by Mr. Speakman came formally into the possession of the society, which formed a kind of jointstock company to pay for it and hold it. Soon after this. Dr. Troost delivered a course of lectures on mineralogy before the academy.
During his residence in Philadelphia Dr. Troost was engaged in manufactures of various kinds. In 1815 or 1816 he began the manufacture of alum on the Magothy River, Cape Sable, Maryland, establishing the first alum works in the United States. In 1821 he was appointed Professor of Mineralogy in the Philadelphia Museum, where he delivered lectures on the subject. He was also appointed about the same time first Professor of Chemistry in the College of Pharmacy, Philadelphia, a position which he resigned, after having delivered one course of lectures, in the succeeding year. During this period he also made geological excursions into New Jersey, New York, and elsewhere.
In 1825 Dr. Troost, with Maclure, Say, and Lesueur, joined Robert Owen in the formation of the Communistic Society at New Harmony, Ind. After remaining there two years, he removed to Nashville, Tenn., in 1827. In 1828 he was elected, at the instance of President Lindley, Professor of Chemistry, Geology, and Mineralogy in the University of Nashville. In a historical sketch, published in the catalogue of 1850, is a table of the longest terms of official service of instructors. It is headed by President Lind-
